New Approachesto
Developing Local Limits
Industrial & Hazardous WasteCommittee Meeting
July 18, 2001
byRichard W. von Langen, P.E.
New Approachesto
Developing Local Limits
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
2
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Sampling Data
• Where?
• What?
• When?
– Residential, Commercial, Industrial, Treatment Plant, Collection System
– POC, Conservative, Non-Conservative, O&G, VOC, TDS, pH
– 1-2 Weeks, Monthly, Quarterly, Weekends, Wet Season, Dry Season
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
3
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Characterizing the Waste andHow Low Can You Go ?
• Metals
• CN, O&G, VOC
• BOD, TSS
• Representative Sampling
• Liquids Versus Sludge
– Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, Zn
– Grab Samples? CN in residential WW ?
– Flow Proportional, Process Water Meters
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
4
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Now… What do I do with the Data?
• Mass Balances
• The “< MDL” Dilemma
• Variable
• When There Isn’t Enough?
– Collection System, Headworks, Plant
– Should the value be used? Assign it a O or =, 50%, or 2/3 of the MDL?
– O to > Avg + 2 SD; SD > 20%, NDs
– Less than 5 (10, 21?) data points
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
5
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Limiting Criteria
• Collection System & Primary Treatment
• Worker Health & Safety
• Biological Treatment Inhibition
• Effluent Limit
• Sludge Disposal
• Air Emissions
– Physical Inhibition or Corrosion
– Airborne, pH related
– EPA Guidance, Plant Data?
– Stream, CTR, Ocean Discharge Limit, Title 22, No Limit
– 503, Fed HW, State-TTLC, STLC
– Odor, VOC
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
6
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Mass BalancesHeadworks data are the fulcrum point for mass balances
Industrial Waste Residential Commercial
EffluentSludge
Headworks
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
7
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Headworks Mass Balance
IW + RES + COM = Headworks
• Effect of Collection System Operations• Lots of NDs• One or Two NDs• No Commercial Samples• Headworks Data Versus Plant Removal• EPA-Within 10-15%
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
8
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Plant Mass Balance
Sludge
Sludge Treatment
HeadworksSecondary Treatment
PrimaryTreatment
Disinfection Effluent
• Chemical Addition• Consumption• Different disposal options• No prim/sec sludge data• Return flows• NDs
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
9
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
American Canyon WWTP Flow Diagram
IndustrialFlow
TreatmentTrain 1
Surface WaterDischarge*
ChlorineDisinfection
UVDisinfection
Reuse asRecycled
Water
Domestic/Commercial
Flow
(Winter)
Sludge HoldingBasin
Landfill LandApplication
Dewatered Sludge
Sludge
Sludge
TreatmentTrains 2, 3, 4
* Instantaneous concentration limits and rolling 12-month mass limits
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
10
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
VCWD WWTP
Sludge
Sludge Treatment
HeadworksSecondaryTreatment
PrimaryTreatment
PercolationPonds
Discharge
TertiaryTreatment
Recycle
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
11
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Example - Aluminum
1.8 X 2.4 = 36#
50#
39#
E - 6#
S - 33#
R - 2.65 x 2.22 = 49#
I - 0.82 x 0.18 = 1#
C- ?
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
12
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Raw Data - Aluminum (mg/L) Residential
#1 #2 #32.9 4.5 2.0
4.7 2.4 2.2
1.6 1.6 4.1
2.3 2.0 2.8
4.1 1.7 3.1
2.8 1.4 3.5
1.7 2.6
Avg – 2.66 SD – 1.01 % SD – 38 Med – 2.4
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
13
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Raw Data - Aluminum (mg/L) Headworks
2.3 Avg – 1.81.8 SD – .351.5 % SD – 201.6 Med – 1.81.91.81.42.41.5
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
14
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Aluminum Local Limit • WDR
• POTW Flow
• POTW % Removal
• MAHL
• Existing Influent
• Uncontrolled Influent
• MAIHL
• Uniform IU Conc. Without Safety Factor
– 1.0 mg/L
– 2.4 MGD
– 84
– 128 lb/day
– 36-50 lbs/day
– 35-49 lbs/day
– 93-79 lbs/day
– 63-53 mg/L
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
15
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Example - Cadmium
R - NDC - ?I - 0.00154#
E - NDS - 0.0021#
ND
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
16
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Raw Data - Cadmium mg/LIndustrial Contribution
#1 #2 #36 days – ND 4 days – ND 6 days – ND
1 day – 0.004 2 days – 0.001 Same process as #2
Residential – ND Headworks – ND Plant Inf/Eff – ND
MDL=0.001
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
17
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Cadmium Local Limit
40 CFR 503 39 mg/Kg CdPOTW % Removal 70%MAHL 0.05787 lb/dayIndustry ContributoryAllocation
0.3 mg/L
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
18
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Example - Silver
R - <DL mg/LC - ?I - 0.00054#
E - ND mg/LS - 0.013#
Headworks<DL
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
19
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Limiting Criteria for Silver
• Process Inhibition
• Pass Through
• Sludge Criteria
– No EPA Criteria
– CTR?, Effluent Limit, WDR, Title 22
– No 503 Requirement, Federal HW? California HW - TTLC, STLC?
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
20
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Mass Balance - Chloride mg/L
R - 44.6C - ?I - 115
Cl2
E - 49S - ?
Headworks44 mg/L
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
21
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
TDS Local LimitsLimiting Criteria - Water Source + 400 mg/L
Approach:– Compute controlled and uncontrolled concentrations of TDS– Subtract (average, highest, lowest?) source water
concentration– Compute MAHL using 400 mg/L and WWTP influent flow– Subtract uncontrolled mass using (average, highest, lowest,
upper quartile, average + 1 SD) uncontrolled sources concentration
– Subtract safety factor– Allocate MAIHL to all Industrial Users
New Approaches to Developing Local LimitsNew Approaches to Developing Local Limits
22
I&HW CommitteeI&HW CommitteeJuly 18, 2001July 18, 2001
Sensitivity Analysis
• NDs
• Variable Data
• Expansion Factor
• Allocation Method• TDS
– Calculate LL at different ND values; adjust headworks concentration to match mass balance
– Eliminate outliers; use geometric mean or median to calculate LL
– Vary; compare to Residential, Commercial, and Industrial Waste contributions
– Total versus contributory IU flows– Vary concentrations of source water,
and uncontrolled sources
Take a Global Perspective